We are running a small experiment where 0.3% of viewers will see an auto-generated thumbnail, instead of your custom thumbnail. We are not removing the ability to create your custom thumbnail, but we hope to gain insights on auto-generated thumbnails for the future.
Will the number of the episode be auto generated on the thumbnail like the other videos in a series? Will the custom art the youtuber paid an artist for be overwritten? Can a youtuber retroactively go back in and reverse it or do they have to re upload?